问题
解答题
用递等式计算(能巧算的要巧算)
218+59+282+141
201×99
5000-(39+22)×62
83×183-83×83
288+36×17÷51
6930÷[235-160÷(31+9)].
答案
(1)218+59+282+141,
=(218+282)+(59+141),
=500+200,
=700;
(2)201×99,
=(200+1)×99,
=200×99+1×99,
=19800+99,
=19899;
(3)5000-(39+22)×62,
=5000-61×62,
=5000-3782,
=1218;
(4)83×183-83×83,
=(183-83)×83,
=100×83,
=8300;
(5)288+36×17÷51,
=288+612÷51,
=288+12,
=300;
(6)6930÷[235-160÷(31+9)],
=6930÷[235-160÷40],
=6930÷[235-4],
=6930÷231,
=30.